Method and device for controlling and/or regulating a sewing machine, sewing machine, and computer software product

ABSTRACT

A method for controlling and/or regulating a sewing machine, in particular an overlock sewing machine, for a sewing operation for mechanically producing a seam ( 1 ) within a base material ( 2 ), the method including the following steps: identifying a sewing operation or an upcoming sewing operation of the sewing machine ( 100 ); setting an upper sewing speed limit (v max ) of the sewing machine ( 100 ); setting a lower sewing speed limit (v max ) of the sewing machine ( 100 ); and carrying out the sewing operation at a sewing speed between the lower sewing speed limit (v min ) and the upper sewing speed limit (v max ). A device ( 10 ) for carrying out the method is provided, and for a sewing machine ( 100 ) having the device ( 10 ), and to a computer software product ( 70 ) for use in the device ( 10 ) or in the sewing machine ( 100 ), respectively, the computer software product ( 70 ) being configured for carrying out the method.

INCORPORATION BY REFERENCE

The following documents are incorporated herein by reference as if fullyset forth: Swiss Patent Application No. 01148/16, filed Sep. 6, 2016.

BACKGROUND

The present invention relates to a method and to a device forcontrolling and/or regulating a sewing machine, in particular anoverlock sewing machine, for mechanically producing a seam within a basematerial. The invention furthermore relates to a sewing machine and to acomputer software product which is configured for use in the sewingmachine.

A so-called overlock sewing machine by way of which in particular theperiphery of one or a plurality of fabrics can be sewn is known in theprior art. It is a particularity of the overlock sewing machine that theperiphery of the fabric or the fabrics, respectively, can besimultaneously joined, neatened and trimmed. Therefore, overlock sewingmachines are also often used for attaching decorative seams to items ofclothing or accessory items. It is particular important in overlockingthat the sewing operator or a user of the sewing machine, respectively,applies the seam to the fabric in as uniform a manner as possible suchthat the required aesthetic appeal is met.

In the case of inexperienced operators it can arise by way of operatingan overlock sewing machine in a non-uniform manner that a seam such asillustrated in FIG. 3A is attached to the fabric or to a base material,respectively, in a relatively non-uniform manner. It also arises morefrequently in the case of complicated stitch patterns that the seam isnot attached to the fabric in a uniform manner as desired. Herein, it isnot only the issue of deficient aesthetics that arises, but there isalso an issue relating to the stitch quality. If an excessively highsewing speed is chosen while the fabric is being guided in an inexpertmanner, in terms of the individual stitch this can lead to a poorstitching quality right up to damage to the sewing machine and/or to thefabric.

In order for these sets of issues to be addressed at least in part, itis proposed in U.S. Pat. No. 5,762,011 that the current sewing speed isadapted so as to depend on a current stitch pattern. It can be derivedfrom U.S. Pat. No. 4,164,192 A that two different maximum sewing speedscan be set for improved control of the sewing operation. Thus, a highermaximum sewing speed can be set for an experienced user of the sewingmachine than for an inexperienced user. However, a stitch pattern ofsatisfactory uniformity, as is desired in particular in the case ofoverlocking, can also not be reliably achieved by these sewing machinesor the corresponding method, respectively.

SUMMARY

It is an object of the present invention to alleviate theafore-described disadvantages at least in part. It is in particular anobject of the present invention to provide an improved method and animproved device for controlling and/or regulating a sewing machine, inparticular an overlock sewing machine, wherein the stitch quality andthe uniformity of a stitch pattern can be improved.

The aforementioned object is achieved by one or more features of theinvention. In particular, the aforementioned object is achieved by themethod according to one or more features of the invention, by the devicehaving one or more features of the invention, by the sewing machinehaving one or more features of the invention, and by the computersoftware product having one or more features of the invention. Furtheradvantages of the invention are discussed below and can be taken fromthe description and from the drawings. The features and details hereinwhich are described in the context of the method of course also apply inthe context of the device, the sewing machine, and the computer softwareproduct according to the invention, and vice versa, respectively, suchthat reference at all times is made or can be made, respectively, in areciprocating manner in terms of the disclosure of the individualaspects of the invention.

According to a first aspect of the present invention, a method forcontrolling and/or regulating a sewing machine, in particular anoverlock sewing machine, for a sewing operation for mechanicallyproducing a seam within a base material is provided. The methodcomprises the following steps:

-   -   identifying a sewing operation or an upcoming sewing operation        of the sewing machine;    -   setting an upper sewing speed limit of the sewing machine;    -   setting a lower sewing speed limit of the sewing machine; and    -   carrying out the sewing operation at a sewing speed between the        lower sewing speed limit and the upper sewing speed limit.

A sewing speed band within which a user is exclusively or substantiallyexclusively permitted to carry out a sewing operation with the sewingmachine can be generated by setting the upper sewing speed limit and thelower sewing speed limit. The sewing operation cannot be carried outeither at an excessively low sewing speed or an excessively high sewingspeed within this defined sewing speed band. Due to this, stitchingfaults can be prevented and the stitching quality during the sewingoperation can be accordingly improved. Moreover, a particularly uniformstitch pattern can be generated in the scope of the sewing speed band,that is to say that loops are not spaced apart from one another in aconspicuously wider or tighter manner in the sewing operation. Due tothis it is possible for even inexperienced users of a sewing machine, inparticular of an overlock sewing machine, to achieve a particularlyuniform stitch pattern of high stitching quality.

The identification of the upcoming sewing operation of the sewingmachine can be understood to mean, for example, that a switching-on ofthe sewing machine is identified and, due to this, the upcoming sewingoperation of the sewing machine. The identification of the upcomingsewing operation of the sewing machine can also be understood to mean,for example, that a wake-up of the sewing machine from a standbyoperation, or the activation of a specific activation means of thesewing machine, is identified and an upcoming sewing operation of thesewing machine is derived based on this. Sewing need not be continuousduring a sewing operation. A short interruption in sewing during thesewing operation can thus be utilized for setting the upper sewing speedlimit and the lower sewing speed limit and for carrying out the sewingoperation at the sewing speed between the upper sewing speed limit andthe lower sewing speed limit. That is to say that a sewing operation canbe identified as such even when no sewing procedure is currently beingcarried out.

The method for controlling and/or regulating the sewing machine can alsobe understood to be a method for carrying out a sewing operation with asewing machine, in particular an overlock sewing machine.

The sewing operation being carried out at a sewing speed between thelower sewing speed limit and the upper sewing speed limit is to beunderstood as the sewing operation being carried out while considering,or adhering to, respectively, the lower sewing speed limit and the uppersewing speed limit. That is to say that the sewing operation is carriedout in such a manner that the upper sewing speed limit is not exceededand the lower sewing speed limit is not undershot. Carrying out thesewing operation can also be understood to be controlling and/orregulating the sewing machine in order for the sewing operation to becarried out.

In setting the upper sewing speed limit, a respective limit value ispreferably selected from a storage device, in particular from anon-volatile storage such as a memory chip of the sewing machine or fromoutside the sewing machine, and is set for the upper sewing speed limit.In setting the lower sewing speed limit, a respective limit value ispreferably selected from a storage device, in particular from anon-volatile storage of the sewing machine or from outside the sewingmachine, and is set for the lower sewing speed limit.

According to one refinement of the present invention, it is possible forat least one parameter of the seam to be produced, of the base materialto be used, and/or of the sewing machine used in the sewing operation,to be identified and the upper sewing speed limit and the lower sewingspeed limit to be set automatically so as to depend on the at least oneparameter identified. For example, a specific type of fabric such ascotton, silk, or leather, or a fabric thickness, can thus be identifiedas a parameter of the base material, and the sewing speed limits can beautomatically set in a corresponding manner. This saves time and thusalso money in terms of the sewing operation. The at least one parameterof the seam to be produced, of the base material, and/or of the sewingmachine used can be measured by way of a sensor device, in particular asensor device of the sewing machine. Due to this, the at least oneparameter can be identified particularly fast and without any furtheroperating steps by a user of the sewing machine. Alternatively, it isconceivable that the at least one parameter of the seam to be produced,of the base material, and/or of the sewing machine used is inputmanually by way of an input device, in particular an input device of thesewing machine such as a touch screen or keyboard. Due to this, the atleast one parameter can be input in a particularly precise manner andcan be identified or used, respectively, in a correspondingly accuratemanner.

In the case of a method according to the invention it is furthermorepossible that a manual modification of the upper sewing speed limit, ora manual modification of the lower sewing speed limit, is identified,and the lower sewing speed limit is modified automatically so as todepend on the manual modification identified of the upper sewing speedlimit, or the upper sewing speed limit is modified automatically so asto be depend on the manual modification identified of the lower sewingspeed limit. Accordingly, a user of the sewing machine has only tomodify the upper sewing speed limit or the lower sewing speed limit, andthe other sewing speed limit is automatically modified. In the case of auser wanting to modify only a sewing speed band, or of the user issupposed to be able to modify only the sewing speed band, respectively,the sewing machine can thus be operated in a particularly simple, rapidand safe manner.

In the context of the present invention it is moreover possible that inthe case of a method the lower sewing speed limit or the upper sewingspeed limit, respectively, are automatically modified as follows:

-   -   when the lower sewing speed limit is manually decreased by a        defined value the upper sewing speed limit is automatically        decreased by the same defined value;    -   when the lower sewing speed limit is manually increased by a        defined value the upper sewing speed limit is automatically        increased by the same defined value;    -   when the upper sewing speed limit is manually decreased by a        defined value the lower sewing speed limit is automatically        decreased by the same defined value;    -   and/or    -   when the upper sewing speed limit is manually increased by a        defined value the lower sewing speed limit is automatically        increased by the same defined value.

Due to this it is possible that a sewing speed band which is formedbetween the upper sewing speed limit and the lower sewing speed limit inthe case of a manual modification of the upper sewing speed limit or ofthe lower sewing speed limit is automatically maintained so as to at alltimes be the same or to be at the same value, respectively. Due to this,any unintentional readjustment of a pre-set sewing speed band can beprevented.

Moreover, it can be advantageous in the case of a method according tothe invention when in the case of a manual modification of the uppersewing speed limit the lower sewing speed limit remains unchanged whenthe manual modification of the upper sewing speed limit is carried outwithin a defined temporal period, in particular within a temporal periodof less than 5 s, following a manual modification of the lower sewingspeed limit, or in the case of a manual modification of the lower sewingspeed limit the upper sewing speed limit remains unchanged when themanual modification of the lower sewing speed limit is carried outwithin a defined temporal period, in particular within a temporal periodof less than 5 s, following a manual modification of the upper sewingspeed limit. That is to say that the sewing speed band between the uppersewing speed limit and the lower sewing speed limit can be modified in acase in which the lower sewing speed limit is manually modified shortlyafter the manual modification of the upper sewing speed limit, or inwhich the upper sewing speed limit is manually modified shortly afterthe manual modification of the lower sewing speed limit. An operator canthus override the fundamental default setting of the sewing speed bandwithout any interfering with the works settings of the sewing machine,and can modify said sewing speed band. Due to this, a comparatively highflexibility can be generated when setting the sewing speed band or theupper and the lower sewing speed limit, respectively. Manualmodifications of the upper sewing speed limit and of the lower sewingspeed limit that are carried out sequentially are possible herein in thesame direction or in different directions.

Moreover, it can be advantageous when in the case of a method accordingto the invention a temporal period of a sewing operation that is carriedout following an automatic modification of the upper sewing speed limitis identified, wherein in the case of a subsequent manual modificationof the upper sewing speed limit the lower sewing speed limit remainsunchanged when the identified temporal period of the sewing operation isshorter than a defined temporal period, in particular is shorter than 5s, or a temporal period of a sewing operation that is carried outfollowing an automatic modification of the lower sewing speed limit isidentified, wherein in the case of a subsequent manual modification ofthe lower sewing speed limit the upper sewing speed limit remainsunchanged when the identified temporal period of the sewing operation isshorter than a defined temporal period, in particular is shorter than 5s. This means in practice, for example, that a manual modification ofthe upper sewing speed limit and consequently an automatic modificationof the lower sewing speed limit and subsequently a short sewingoperation over, for example, less than 5, preferably less than 3seconds, take place. The user of the sewing machine now notices thathe/she would rather sew in a wider sewing speed band, thus at a largerspacing between the upper sewing speed limit and the lower sewing speedlimit. Should said operator now decide to readjust the lower sewingspeed limit even further downward, or to decrease said lower sewingspeed limit, respectively, this does not have any have any influence onthe supper sewing speed limit. Due to this, a particularly highflexibility in the setting of the sewing speed band, or of the upper andthe lower sewing speed limit, can be generated even during a sewingoperation or between two sewing procedures of one sewing operation,respectively.

In one further design embodiment of the present invention it isconceivable that a defined sewing speed range only in which the uppersewing speed limit and the lower sewing speed limit can be or arepermitted to be modified, respectively, is set. This is to say that whenthe sewing machine has a maximum sewing speed of 1500 stitches perminute (st/min), for example, the defined sewing speed range is set to arange between 500 and 1000 st/min. A sewing speed band of 500 st/min,for example, can be freely displaced in this range, but not beyond thelimits of the defined sewing speed range. Due to this, a certain degreeof safety can be achieved as opposed to a sewing speed band that isvariable in an excessively arbitrary manner. Due to this, it canmoreover be prevented that a machine is constantly operated at themaximum possible sewing speed, for example. This can promote thelongevity of the sewing machine.

It is furthermore possible that in the case of a method according to theinvention an acoustic and/or visual warning signal is triggered when theupper sewing speed limit and/or the lower sewing speed limit exceed orundershoot, respectively, a defined limit threshold value. A definedsewing speed range in which a sewing speed band can be modified in analarm-free manner can thus be set, for example. However, an alarm istriggered as soon as an upper or a lower sewing speed limit of thedefined sewing speed band is exceeded or undershot, respectively. Thiscan alert the user to now being in a range of a sewing speed in he/sheshould not or must not sew. Due to this, potential damage or destructionof the sewing machine and/or of the base material can be prevented.

In the context of the present invention it is moreover possible that anacoustic and/or visual alarm signal is triggered when a difference valuebetween the upper sewing speed limit and/or the lower sewing speed limitexceeds a defined difference threshold value. Due to this, a user of thesewing machine can be alerted when an excessively large sewing speedband is or would be generated by modifying the upper sewing speed limitand the lower sewing speed limit. The uniform stitch pattern and/or thestitching quality could no longer be reliably guaranteed on account ofan excessively large sewing speed band. It is also conceivable hereinthat a defined sewing speed range is set in such a manner that thedefined difference threshold value cannot be exceeded.

According to another aspect of the present invention, a device forcontrolling and/or regulating a sewing machine, in particular anoverlock sewing machine, for a sewing operation for mechanicallyproducing a seam within a base material is provided, wherein the deviceis designed for carrying out a method as has been described in detailabove. A device according to the invention thus offers the sameadvantages as have been described in detail with reference to the methodaccording to the invention. The device preferably has an identificationdevice for identifying a sewing operation or an upcoming sewingoperation of the sewing machine. Moreover, the device has a settingdevice for setting the upper sewing speed limit of the sewing machineand for setting the lower sewing speed limit of the sewing machine. Theidentification device and the setting device can be designed andconfigured as a component part of a control unit of the sewing machineor for the sewing machine, respectively. The control unit can likewisebe designed for carrying out the sewing operation at the sewing speedbetween the lower sewing speed limit and the upper sewing speed limit,and the other method steps as have been explained in detail above.

According to one refinement of the device according to the invention, itis possible that a user of the sewing machine by way of the input deviceis capable of manually setting whether or not the manual modification ofthe upper sewing speed limit results in the automatic modification ofthe lower sewing speed limit, or the manual modification of the lowersewing speed limit results in the automatic modification of the uppersewing speed limit. The input device is preferably disposed and designedso as to be directly on the sewing machine. The input device can bedesigned as a touch-sensitive display and/or as mechanical activationelements. For the setting above, for example, the input device candisplay or have a check box, respectively, which can be selecteddepending on whether the manual modification of the upper sewing speedlimit is to result in the automatic modification of the lower sewingspeed limit, or the manual modification of the lower sewing speed limitis to result in the automatic modification of the upper sewing speedlimit. The setting by way of the check box can be performed in amechanical or capacitive manner, so as to depend on the designembodiment of the input device. Settings of this type can be carried outon the sewing machine in a particular simple and user-friendly manner byway of such an input device. As an alternative to a check box, a sliderby way of which the setting being discussed can be performed, forexample by displacing the slider to the left or the right, can also beillustrated on the input device.

In the case of a device according to the invention it is furthermorepossible that the device is configured and designed in such a mannerthat the upper sewing speed limit remains unchanged when the lowersewing speed limit is manually increased, or the lower sewing speedlimit remains unchanged when the upper sewing speed limit is manuallydecreased. That is to say that when a sewing speed band is beingdecreased, a manual modification of one sewing speed limit should notresult in the automatic modification of the other sewing speed limit. Inthe case of the decrease in the sewing speed band, the stitching qualityand a uniformity of the stitching pattern tend to increase. Due to thepresent configuration of the device, the sewing speed band can thus bemodified in a simple manner in specific advantageous cases. However, theupper sewing speed limit should preferably be automatically increased,as has been described above, when the lower sewing speed limit ismanually increased, or the lower sewing speed limit should beautomatically decreased when the upper sewing speed limit is decreased,as has been described above, respectively.

A further advantage of the present invention can be derived from thesewing machine having a storage device and from various seam-specific,base-material specific, and/or sewing-machine specific upper sewingspeed limits and lower sewing speed limits being stored in the storagedevice. These limit values can be accessed immediately upon starting-upthe sewing machine, and the sewing machine can be set in an automaticand accordingly fast manner using suitable base limit values. When thebase material or the fabric or fabrics, respectively, to be sewn areknown, which can be assumed in the typical case, the sewing machine canbe provided information pertaining to the base material, and the sewingmachine can set directly the base-material specific upper sewing speedlimits and the lower sewing speed limits. The storage device can have atleast one volatile and/or non-volatile storage, for example a RAM orEPROM. The storage device preferably has both one volatile as well asone non-volatile storage, wherein various seam-specific, base-materialspecific, and/or sewing-machine specific upper sewing speed limits andlower sewing speed limits are stored as base limit values in thenon-volatile storage.

Moreover, it can be advantageous according to the invention when varioususer-specific upper sewing speed limits and lower sewing speed limitsare stored in the storage device. These values can also be accesseddirectly upon the starting-up of the sewing machine, and the sewingmachine can be set in an automatic and accordingly fast manner usingsuitable user-specific base parameters. The degree of experience of theuser can thus be input into the sewing machine, for example by way ofthe input device, prior to the start of the sewing operation, forexample, and said sewing machine can set directly the respectiveuser-specific upper sewing speed limits and lower sewing speed limits.

Moreover, various combinations of sewing speed limits can of course alsobe stored in the storage device, said combinations being, for example, acombination of user-specific upper sewing speed limits and lower sewingspeed limits, and base-material specific upper sewing speed limits andlower sewing speed limits. The degree of experience of the user and thebase material used can thus be input into the sewing machine, forexample, by way of the input device, and said sewing machine can setdirectly the respective combination of sewing speed limits in relationto the degree of experience of the user and to the base material used.

According to one further design embodiment of the present invention itis possible that an upper sewing speed limit and/or a lower sewing speedlimit, modified according to the method described above, are/is capableof being stored, in particular manually stored, in the storage device byactivating an input means of the device. Favorites which can be accessedagain during a later sewing operation can thus be created during thesewing operation or thereafter, in particular when said favorites, as ispreferably possible, are stored or capable of being stored,respectively, in a non-volatile storage of the storage device. It isfurthermore possible that a defined number of the used or modifiedsewing speed limits, respectively, are automatically stored as a profileor a history in the storage device. The sewing operation can bedocumented if the various values are stored in a non-volatile storage,for example. Storing the values being discussed in a volatile storagehas the advantage that settings that date back to a temporally briefperiod, or corresponding upper sewing speed limits and lower sewingspeed limits, respectively, can be accessed in a simple and fast manner.

In the case of a device according to the invention it is moreoverpossible that the modified upper sewing speed limits and/or the modifiedlower sewing speed limits pertaining to a specific seam, a specific basematerial and/or a specific sewing machine are capable of being stored,in particular manually stored, in the storage device by activating aninput means of the device. Favorites in relation to a specific seam, toa specific base material, and/or to a specific sewing machine can thusbe created during the sewing operation or after the sewing operation.The favorites can be accessed again during a later sewing operation, inparticular when these favorites, as is preferably possible, are storedor are capable of being stored, respectively, in a non-volatile storageof the storage device.

It can be furthermore advantageous for the device to have a resetfunction by way of which the stored modified upper sewing speed limitand/or lower sewing speed limit in the storage device can be deleted.For example, if the device is used for a new sewing machine, or if thestitch pattern changes, stored values which no longer have anysignificance for the upcoming sewing operations can be deleted, andstorage space can be created for new values in a fast and simple manner.

According to a further aspect of the present invention, a sewingmachine, in particular an overlock sewing machine, for mechanicallyproducing a seam within a base material is provided, said sewing machinehaving a device as described in detail above. The sewing machineaccording to the invention thus offers the same advantages as have beendescribed in detail with reference to the device according to theinvention.

Moreover, a computer software product according to the invention for usein a sewing machine and/or in a device such as has been described indetail above is provided, wherein the computer software product isconfigured in such a manner that a method as has been described indetail above is carried out by the sewing machine in the production of aseam within a base material. A computer software product according tothe invention thus also offers the same advantages as have beendescribed in detail with reference to the device according to theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further measures that improve the invention are derived from thedescription hereunder of various exemplary embodiments of the invention,which are schematically illustrated in the figures. All the featuresand/or advantages which can be gathered from the claims, from thedescription or from the drawings, including design details and spatialarrangements, may be essential to the invention both in their own rightor in a wide variety of different combinations.

In the figures, in each case in a schematic manner:

FIG. 1 shows an overlock sewing machine according to the invention;

FIG. 2 shows a device according to the invention for controlling and/orregulating the overlock sewing machine;

FIG. 3A shows a non-uniform stitch pattern;

FIG. 3B shows a uniform stitch pattern;

FIG. 4 shows an input device according to the invention in a firstoperating state, according to a first embodiment;

FIG. 5 shows an input device according to the invention in a secondoperating state, according to the first embodiment;

FIG. 6 shows an input device according to the invention in a thirdoperating state, according to the first embodiment;

FIG. 7 shows an input device according to the invention in a fourthoperating state, according to the first embodiment;

FIG. 8 shows an input device according to the invention in a fifthoperating state, according to the first embodiment;

FIG. 9 shows an input device according to the invention, according to asecond embodiment;

FIG. 10 shows an input device according to the invention, according to athird embodiment;

FIG. 11 shows a flow chart for explaining a method according to theinvention, according to a first embodiment;

FIG. 12 shows a flow chart for explaining a method according to theinvention, according to a second embodiment;

FIG. 13 shows a flow chart for explaining a method according to theinvention, according to a third embodiment;

FIG. 14 shows a flow chart for explaining a method according to theinvention, according to a fourth embodiment; and

FIG. 15 shows a flow chart for explaining a method according to theinvention, according to a fifth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Elements with identical functions and operating modes are provided withthe same reference signs in each of FIGS. 1 to 15.

A sewing machine 100 in the form of an overlock sewing machine isschematically illustrated in FIG. 1. The sewing machine 100 has a device10 such as a controller for controlling and/or regulating the sewingmachine 100. The device 10 has an input device 20 in the form of atouch-sensitive display.

FIG. 2 shows a block circuit diagram for explaining the device 10. Thedevice 10, apart from the input device 20, has a non-volatile storage30, a volatile storage 40, a motor 50 for driving the sewing machine100, and a motor controller 60. A computer software product 70 accordingto the invention which by way of the motor controller 60 can be run forcontrolling and/or regulating the sewing machine 100 is stored in thenon-volatile storage 30. Moreover, various seam-specific, base-materialspecific, and/or sewing-machine specific upper sewing speed limits andlower sewing speed limits are stored in the non-volatile storage 30.Moreover, various user-specific upper sewing speed limits and lowersewing speed limits are stored in the non-volatile storage 30.

Various operating parameters such as, for example, an upper sewing speedlimit v_(max) and a lower sewing speed limit v_(min) can be set by wayof the input device 20. The motor controller 60 serves in particular forsetting the desired sewing speed by mutually matching and adapting anominal sewing speed and an actual sewing speed. The actual sewing speedcan be obtained by the motor controller 60 by way of devices and methodsthat are known in the prior art. The nominal sewing speed is obtained bythe motor controller 60 by way of an input by the user by way of theinput device 20, or by reading the non-volatile storage 30 and/or thevolatile storage 40.

The device 10 furthermore has a reset function by way of which a storedand potentially modified upper sewing speed limit and/or a lower andpotentially modified sewing speed limit can be deleted in thenon-volatile storage 30 and/or in the volatile storage 40.

A non-uniform stitch pattern or seam image N1 on a base material 2 isillustrated in FIG. 3A. The seam 1 shown in FIG. 3A is the result of asewing operation at sewing speeds that differ widely from one another.

A uniform stitch pattern or seam image N2 on the base material 2 isillustrated in FIG. 3B. The seam 1 shown in FIG. 3B is the result of asewing operation according to the invention which has been carried outat a sewing speed between an upper sewing speed limit v_(max) and alower sewing speed limit v_(min).

FIG. 4 shows an input device 20 having a display 21 for an upper sewingspeed limit v_(max), adjustment panels 22 for modifying the upper sewingspeed limit v_(max), a display 23 for a lower sewing speed limitv_(min), adjustment panels 24 for modifying the lower sewing speed limitv_(min), a slider 25 for modifying the upper sewing speed limit v_(max),and a slider 26 for modifying the lower sewing speed limit v_(min). FIG.4 shows an input device 20 on which basic settings are illustrated oncethe sewing machine 100 has been switched on. The basic settingsaccordingly are an upper sewing speed limit v_(max) of 1000 st/min and alower sewing speed limit v_(max) of 500 st/min.

A first embodiment of the present invention will be subsequentlydescribed with reference to FIG. 4 and FIG. 11. To this end, an ongoingor an intended sewing operation is initially identified. An upcomingsewing operation is identified in that switching-on of the sewingmachine 100 is identified, for example. The upper sewing speed limitv_(max) and the lower sewing speed limit v_(min) are subsequently set,as is illustrated in FIG. 4. Thereafter, a sewing operation is carriedout while adhering to the upper sewing speed limit v_(max) and to thelower sewing speed limit v_(min).

A second embodiment of the present invention will be subsequentlydescribed with reference to FIG. 4, FIG. 5 and FIG. 12. For the sake ofsimplification, a repetition of method steps that have already beendescribed will be dispensed with. Upon identification of the sewingoperation, a stitch pattern is selected. Depending on the stitch patternselected, the upper sewing speed limit v_(max) is now set to 1000st/min, and the lower sewing speed limit v_(min) to 500 st/min. Should amanual increase of the lower sewing speed limit v_(min) from 500 st/minto v_(min+)=700 st/min now be identified, the upper sewing speed limitv_(max) is automatically also increased by 200 st/min, thus from 1000st/min to v_(max+)=1200 st/min, as is illustrated in FIG. 5. A sewingspeed band between the new lower sewing speed limit v_(min+) and the newupper sewing speed limit v_(max+) consequently remains identical at avalue of 500 st/min. A sewing operation is subsequently carried outwhile adhering to the new sewing speed limits v_(max+), v_(min+).

A third embodiment of the present invention will be described hereunderwith reference to FIG. 4, FIG. 5, FIG. 6, FIG. 7 and FIG. 13. Initially,the first five steps are carried out as has been described withreference to the second embodiment. A step in which it is determined oridentified, respectively, whether a sewing operation has or has not beencarried out since the automatic increase of the upper sewing speed limitv_(max) now follows. If no sewing operation has been carried out, and ifa manual increase of the upper sewing speed limit v_(max) from 1200st/min to 1300 st/min in a direct manner, for example within 5 s, isdetected, as illustrated in FIG. 7, the lower sewing speed limitv_(min+) is maintained, and the sewing operation is subsequently carriedout between these limit values.

By contrast, if it is detected that a sewing operation has been carriedout, a differentiation pertaining to the length of the latter isinitially performed. Herein a differentiation as to whether the sewingoperation has continued for more or less than 5 s is performed. If thesewing operation has continued for more than 5 s, it is assumed that asewing operation has been concluded and a new sewing operation is tocommence. If a manual increase of the upper sewing speed limit v_(max+)from 1200 to v_(max++)=1300 st/min is now identified, as is illustratedin FIG. 6, the lower sewing speed limit v_(min+) is also automaticallyincreased from 700 st/min to v_(min++)=800 st/min. Thereafter, a sewingoperation is carried out between the upper sewing speed limit v_(max++)and the lower sewing speed limit v_(min++).

Should the sewing operation have continued for less than 5 s, it isassumed that the sewing operation has not yet been concluded and thatthe sewing speed band is to be readjusted. If a manual increase of theupper sewing speed limit v_(max+) from 1200 to v_(max++)=1300 st/min isidentified, as is illustrated in FIG. 7, the lower sewing speed limitv_(min+) is maintained and a sewing operation is subsequently carriedout between the upper sewing speed limit v_(max++) and the lower sewingspeed limit v_(max+).

A fourth embodiment of the present invention will be subsequentlydescribed with reference to FIG. 4, FIG. 8 and FIG. 14. The first foursteps of the fourth embodiment again correspond in principle to thefirst four steps of the second and the third embodiment. However, it issubsequently determined or identified, respectively, whether the sewingspeed band will become larger or smaller by modifying the lower sewingspeed limit v_(min). In order for the risk of a non-uniform stitchpattern to be reduced, the sewing speed band according to thisembodiment must not become larger. That is to say, if it is nowidentified that by decreasing the lower sewing speed limit v_(min) thesewing speed band will or could become larger, respectively, the uppersewing speed limit v_(max) is automatically decreased by the value ofthe decrease of the lower sewing speed limit v_(min). A sewing operationat a sewing speed band that has remained the same is subsequentlycarried out. However, if it is established that by increasing the lowersewing speed limit v_(min) the sewing speed band will or would becomesmaller, respectively, the upper sewing speed limit v_(max) ismaintained, as is illustrated in FIG. 8. A sewing operation issubsequently carried out at a reduced sewing speed band.

A fifth embodiment of the present invention, in which it can be selectedby way of a check box 27 whether a modification of a sewing speed bandis to be permissible or not, will be described hereunder with referenceto FIG. 9 and FIG. 15. A modification of the sewing speed band is notpermissible if the “YES” area is selected or activated, as isillustrated in FIG. 9. If a sewing speed limit is now modified, theother sewing speed limit is forcibly and conjointly modified. However, amodification of the sewing speed band in the context of the embodimentsillustrated above is permissible or possible, respectively, if the “NO”area is selected or activated, respectively (not illustrated).

FIG. 10 shows a further embodiment of the input device 20 in which asewing speed band 28 is illustrated graphically on a touch-sensitivesurface of the input device 20. In this case, a user by way of his/herfinger 3 or another activation device can displace directly the sewingspeed band 28 or the associated sewing speed limits in the context ofthe of the permissibility as illustrated above. As soon as the sewingspeed band 28 or a sewing speed band of the other embodiments has beenset, said sewing speed band can be stored manually or automatically inthe non-volatile storage 30 or in the volatile storage 40.

LIST OF REFERENCE SIGNS

-   -   1 Seam    -   2 Base material    -   3 Finger    -   10 Device    -   20 Input device    -   21 Display for upper sewing speed limit    -   22 Adjustment panels for modifying the upper sewing speed limit    -   23 Display for lower sewing speed limit    -   24 Adjustment panels for modifying the lower sewing speed limit    -   25 Slider for modifying the upper sewing speed limit    -   26 Slider for modifying the lower sewing speed limit    -   27 Check box    -   28 Sewing speed band for modifying the upper and the lower        sewing speed limit    -   30 Non-volatile storage    -   40 Volatile storage    -   50 Motor    -   60 Motor controller    -   100 Sewing machine    -   vmax Upper sewing speed limit    -   vmin Lower sewing machine limit    -   MAX Maximum sewing speed of the sewing machine    -   MIN Minimum sewing speed of the sewing machine

1. A method for at least one of controlling or regulating a sewingmachine (100) for a sewing operation for mechanically producing a seam(1) within a base material (2), said method comprising the followingsteps: identifying a sewing operation or an upcoming sewing operation ofthe sewing machine (100); setting an upper stitch-specific sewing speedlimit (v_(max)) of the sewing machine (100); setting a lowerstitch-specific sewing speed limit (v_(min)) of the sewing machine(100); and carrying out the sewing operation at a sewing speed betweenthe lower stitch-specific sewing speed limit (v_(min)) and the upperstitch-specific sewing speed limit (v_(max)).
 2. The method as claimedin claim 1, further comprising identifying at least one parameter of theseam (1) to be produced, of the base material (2) to be used, or of thesewing machine (100) used in the sewing operation, and automaticallysetting the upper stitch-specific sewing speed limit (v_(max)) and thelower stitch-specific sewing speed limit (v_(min)) dependent on the atleast one parameter identified.
 3. The method as claimed in claim 1,further comprising identifying a manual modification of the upperstitch-specific sewing speed limit (v_(max)) or a manual modification ofthe lower stitch-specific sewing speed limit (v_(min)), andautomatically modifying the lower stitch-specific sewing speed limit(v_(min)) dependent on the manual modification identified of the upperstitch-specific sewing speed limit (v_(max)), or automatically modifyingthe upper stitch-specific sewing speed limit (v_(max)) dependent on themanual modification identified of the lower stitch-specific sewing speedlimit (v_(min)).
 4. The method as claimed in claim 3, wherein the lowerstitch-specific sewing speed limit (v_(min)) and the upperstitch-specific sewing speed limit (v_(max)), respectively, areautomatically modified according to at least one of the following: whenthe lower stitch-specific sewing speed limit (v_(min)) is manuallydecreased by a defined value the upper stitch-specific sewing speedlimit (v_(max)) is automatically decreased by the same defined value;when the lower stitch-specific sewing speed limit (v_(min)) is manuallyincreased by a defined value the upper stitch specific sewing speedlimit (v_(max)) is automatically increased by the same defined value;when the upper stitch-specific sewing speed limit (v_(max)) is manuallydecreased by a defined value the lower stitch-specific sewing speedlimit (v_(min)) is automatically decreased by the same defined value; orwhen the upper stitch-specific sewing speed limit (v_(max)) is manuallyincreased by a defined value the lower stitch-specific sewing speedlimit (v_(min)) is automatically increased by the same defined value. 5.The method as claimed in claim 3, wherein in the case of the manualmodification of the upper stitch-specific sewing speed limit (v_(max))the lower stitch-specific sewing speed limit (v_(min)) remains unchangedwhen the manual modification of the upper stitch-specific sewing speedlimit (v_(max)) is carried out within a defined temporal periodfollowing a manual modification of the lower stitch-specific sewingspeed limit (v_(min)), or in the case of the manual modification of thelower stitch-specific sewing speed limit (v_(min)) the upperstitch-specific sewing speed limit (v_(max)) remains unchanged when themanual modification of the lower stitch-specific sewing speed limit(v_(min)) is carried out within a defined temporal period following amanual modification of an upper stitch-specific sewing speed limit(v_(max)).
 6. The method as claimed in claim 3, further comprisingidentifying a temporal period of a sewing operation that is carried outfollowing an automatic modification of the upper stitch-specific sewingspeed limit (v_(max)), and in in the case of a subsequent manualmodification of the upper stitch-specific sewing speed limit (v_(max))the lower stitch-specific sewing speed limit (v_(min)) remains unchangedwhen the identified temporal period of the sewing operation is shorterthan a defined temporal period or a temporal period of a sewingoperation that is carried out following an automatic modification of thelower stitch-specific sewing speed limit (v_(min)) is identified, and inthe case of a subsequent manual modification of the lowerstitch-specific sewing speed limit (v_(min)) the upper stitch-specificsewing speed limit (v_(max)) remains unchanged when the identifiedtemporal period of the sewing operation is shorter than a definedtemporal period.
 7. The method as claimed in claim 1, further comprisingsetting a defined sewing speed range only in which the upperstitch-specific sewing speed limit (v_(max)) and the lowerstitch-specific sewing speed limit (v_(min)) can be modified.
 8. Themethod as claimed in claim 7, further comprising triggering at least oneof an acoustic or visual warning signal when at least one of the upperstitch-specific sewing speed limit (v_(max)) or the lowerstitch-specific sewing speed limit (v_(min)) exceed(s) or undershoot(s),respectively, a defined limit threshold value.
 9. The method as claimedin claim 7, further comprising triggering at least one of an acoustic orvisual warning signal when a difference value between at least one ofthe upper stitch-specific sewing speed limit (v_(max)) or the lowerstitch-specific sewing speed limit (v_(min)) exceeds a defineddifference threshold value.
 10. A device (10) for at least one ofcontrolling or regulating a sewing machine (100) for a sewing operationfor mechanically producing a seam (1) within a base material (2)configured to carry out the method of claim
 1. 11. The device (10) asclaimed in claim 10, comprising an input device (20) configured to allowa user of the sewing machine (100) to manually set whether or not amanual modification of the upper stitch-specific sewing speed limit(v_(max)) results in an automatic modification of the lowerstitch-specific sewing speed limit (v_(min)), or a manual modificationof the lower stitch-specific sewing speed limit (v_(min)) results in anautomatic modification of the upper stitch-specific sewing speed limit(v_(max)).
 12. The device (10) as claimed in claim 10, wherein thedevice (10) is configured such that the upper stitch-specific sewingspeed limit (v_(max)) remains unchanged when the lower stitch-specificsewing speed limit (v_(min)) is manually increased, or the lowerstitch-specific sewing speed limit (v_(min)) remains unchanged when theupper stitch-specific sewing speed limit (v_(max)) is manuallydecreased.
 13. The device (10) as claimed in claim 10, furthercomprising a storage device (30, 40) configured to store at least one ofvarious seam-specific, base-material specific, or sewing-machinespecific upper sewing speed limits (v_(max)) and lower sewing speedlimits (v_(min)).
 14. The device (10) as claimed in claim 10, furthercomprising a storage device (30, 40) configured to store varioususer-specific upper sewing speed limits (v_(max)) and lower sewing speedlimits (v_(min)).
 15. The device (10) as claimed in claim 10, furthercomprising a storage device (30, 40) and an input device, the storagedevice is configured to store at least one of an upper stitch-specificsewing speed limit (v_(max)) or a lower stitch-specific sewing speedlimit (v_(min)) by activating the input device.
 16. The device (10) asclaimed in claim 11, further comprising an input device, and the storagedevice is configured to store at least one of the modified upper sewingspeed limits (v_(max)) or the modified lower stitch-specific sewingspeed limits (v_(min)), pertaining to at least one of a specific seam(1), a specific base material (2) or a specific sewing machine (100) byactivating the input device.
 17. The device (10) as claimed in claim 16,wherein the device (10) has a reset function by way of which at leastone of the stored modified upper stitch-specific sewing speed limit(v_(max)) or the lower stitch-specific sewing speed limit (v_(min)) inthe storage device 30, 40) can be deleted.
 18. A sewing machine (100)for mechanically producing a seam (1) within a base material (2), havingthe device as claimed in claim
 10. 19. A computer software product (70)stored on a fixed memory and configured to carry out the method asclaimed in claim 1 on a sewing machine (100) for production of a seam(1) within a base material (2).